Method and apparatus for filling and emptying collapsible containers



Oct. 29, 1957 M. M. CUNNINGHAM 2,811,178 METHOD AND APPARATUS FOR FILLING AND EMPTYING Filed June 28, 1955 COLLAPSIBLE CONTAINERS 4 Sheets-Sheet 1 iZMZJW ATTORNEY S M R m an Wm cm H M L m MC.

' Oct. 29, 1957 METHOD AND APPARATUS FOR FILLING AND EMPTYING Filed June 28, 1955 4 Sheets-Sheet 2 INVENTOR. fl/A/P/d/V/i a/Mm a/m/v ATTORNEY Oct. 29, 1957 M. M. CUNNINGHAM METHOD AND APPARATUS FOR FILLING AND EMPTYING COLLAPSIBLE CONTAINERS 4 Sheets-Sheet 3 Filed June 28, 1955 ATTORNEY Oct. 29, 1957 M. M. CUNNINGHAM 2,

METHQD AND APPARATUS FOR FILLING AND EMPTYING COLLAPSIBLE CONTAINERS Filed June 28, 1955 4 Sheets-Sheet 4 "H'Illlllllllllllllllll IIIIIIIIIIIIIIIIIIHIIII 5 INVENTOR.

ATTORNEY United States ateflt METHOD AND APPARATUS FOR FILLING AND EMPTYING COLLAPSIBLE CONTAINERS Marion M. Cunningham, Providence, R. L, assignor to United States Rubber Company, New York, N. Y., a corporation of New Jersey Application June 28, 1955, Serial No. 518,538

15 Claims. ((11. 141-6) This invention relates to a method and apparatus for filling and emptying large collapsible shipping containers of the type generally shown in my United States Patent No. 2,612,924.

It was originally suggested that containers of this type be first filled with the material to be shipped or stored and then, after filling, pressurized by the introduction of gas under pressure thereto to make the containers rigid so that they could be easily handled, stored and stacked. While such a method is quite satisfactory for comparatively small containers, it is not particularly satisfactory for larger containers.

In accordance with the method of my present inven tion, the container is first pressurized to expand the container to its full size and then while so pressurized and expanded, filled with the material to be shipped. By initially expanding the container and maintaining the container expanded during the filling thereof, utilization of the full storage capacity of the container is obtained. It is contemplated that in most instances air will be used to pressurize the container but where the material to be shipped is subject to contamination by or presents a hazardous condition in the presence of air, a suitable inert gas, such as nitrogen, can be used.

The apparatus of my invention is intended to be used in performing the method of the invention and includes apparatus for pressurizing and filling the collapsible container through separate openings in the container or the same opening.

Other objects and advantages of the present invention will become apparent from the following description when read in conjunction with the accompanying drawings wherein:

Fig. l is an elevational view, partly in section, showing one form of apparatus for filling a collapsible container in accordance with the invention;

Fig. 2 is an enlarged partial elevational view showing the connection between the apparatus of Fig. 1 and the collapsible container;

Fig. 3 is an elevational view of another form of apparatus for filling collapsible containers in accordance with the invention;

Fig. 4 is an enlarged sectional view showing the connection between the apparatus of Fig. 3 and the collapsible container;

Fig. 4A is an enlarged sectional view showing another form of connection between the filling apparatus and the collapsible container;

Fig. 5 is an elevational view, partly in section, of still another form of apparatus for filling a collapsible container in accordance with the invention;

Fig. 6 is a sectional view of a modified form of the apparatus shown in Fig. 5;

Fig. 7 is a sectional view of a pressure regulator and gas cleaner usable with any one of the forms of the apparatus illustrated;

Fig. 8 is an elevational view of a device for dispersing r CC the filling material towards the sides of the container during filling of the container; and

Fig. 9 is an elevational view showing apparatus for use in discharging material from a collapsible container.

Referring to the drawings and in particular to Fig. 1, there is shown a collapsible container, designated by the letter C, of the general type with which the apparatus and method of the present inventionis intended to be used. The container is formed of flexible cord fabric which is covered and impregnated with rubber (either natural or synthetic) to render the fabric gas and liquid tight. Neoprene rubber has been found to be particularly suitable for covering and impregnatingthe fabric,

The container when inflated is of a generally cylindrical shape and is provided at one end with a central lifting eye L by which the container may be lifted by suitable means, such as the overhead traveling chain hoist H, illustrated. A filling opening F is provided in the top of the container to one side of the lifting eye L and a discharge opening D is provided in the bottom of the container.

As best shown in Fig. 2, a flexible fabric, preferably nylon, sock or sleeve S is secured to the fitting F of the filling opening F. As will be described, the sock or sleeve S may be utilized in making a connection with the filling apparatus. The sleeve or sock S is provided with two tie strings T andT by which the sleeve or sock S may be closed. The sleeve S is preferably treated or coated to render it gas impervious so that when tied up by one of the tie strings it forms a secondary closure for the container. Such a sleeve is commonly referred to as a sleeve valve. When not in use during shipment or storage of the container, the sleeve or sock S is tucked into the opening F and covered by the usual closure plug of cap. The discharge opening D is similarly provided with a sleeve or sock.

An inflating opening I is provided in the container adjacent the filling opening through which an inflating gas may be introduced. The inflating opening is cornmonly provided with a check valve to facilitate inflation of the container and prevent escape of gas from the container during shipment or storage.

Steel reinforcing cables W, secured at one end to the lifting eye L and at the other end to space points to the lower end of the container serve to permit bulging of the ends of the container and to take a portion of the load during lifting of the container. The container is generally of the type described in my U. S. Patent No. 2,612,924, which is assigned to the same assignee as the instant application, and reference is made thereto for a more detailed description of the structure thereof.

In filling the container C by use of the apparatus shown in Fig. l, and in accordance with the method of the invention, the container C, while collapsed and supported by chain hoist H, is inflated to expand it to its full size by the introduction of gas under pressure into'the container through the inflating valve I prior to the filling thereof with the filling material. The inflating gas may be air or, if the nature of the filling material requires, an inert gas, such as nitrogen, may be used. A gas pressure of from /2 to 1 pound per square inch is usually sufiicient to expand the container to its full size.

The gas under pressure is supplied to the container C from a pump 10 through a pipe 11 and through a flexible hose 12 which is connected to the inflating opening I of the container C. As previously described, the inflating opening I is preferably provided with a conventional check valve to prevent escape of air when the hose 12 is uncoupled but which will allow the gas to flow in both directions when the hose is coupled to the container.

After the container is expanded to its full size, it is ready to be filled. In accordance with the invention, the container is filled against the pressure in the container, i. e., sufficient pressure above atmospheric pressure is maintained in the container during filling to insure that the container is expanded to its full size during filling thereby insuring utilization of the full capacity of the container.

The granular or powdered filling material with which the container is to be filled is conveniently conveyed from a suitable storage hopper or bin 13 to a point above the container C, by means of a suitable screw conveyor 14. From the conveyor 14, the filling material passes vertically downwardly through a conventional rotary gas lock valve 14 which allows the filling material to pass therethrough but prevents the gas under pressure from escaping from the container C. From the rotary valve 155 the filling material passes through a flexible conduit 16 through a rigid end nozzle 17 through the filling opening F into the container. A substantially gas tight connection between the nozzle 17 and the container C is conveniently made by utilizing the flexible sleeve or sock S which, as previously described, is secured to the filling opening F of the container. The sock S is slipped over the nozzle 17 and tied tightly thereto by the tie string T or by some other suitable means, such as a heavy rubber band or conventional hose clamp.

As previously described, the gas lock valve permits the filling material to pass into the container but prevents a loss of the gas under pressure from the container. The gas lock valve 15 is a conventional valve, and in the simplest form consists of a freely rotatable rotor having radiating blades 15a, the ends of which have a very small clearance with the surrounding housing 15b. The gas under pressure in the container acts on the blades on both sides of the center of rotation of the rotor with equal pressure with the result that the rotor does not turn under the influence of the gas pressure. On the other hand, the filling material is directed against the blades only on one side of the center rotation of the valve with the result that the valve rotor turns admitting the filling material to the container.

The connection of the sleeve or sock S to the nozzle 17 may be made either before or after the container is inflated or pressurized. In the event that the container is pressurized before making the connection, the intermediate tie string T is not unfastened until the connection of the free end of the sleeve or sock S is made, so that the gas will not escape from the container While the connection is being made. After the connection is made, the tie string T is unfastened to permit filling material to pass through the sleeve.

In collapsed condition, the container C will contain very little air and in instances where an inert gas is used to inflate the container, it is not normally necessary to purge the container of the little air that it might contain in the collapsed condition. However, if it is important that all air be removed, the container can be purged with either the inert gas or a liquid to remove all air.

If desired, the pump 10 which pumps the gas into the container may be operated continuously during the filling operation to insure maintenance of the inflation of the container. However, in most instances, the volume of the filling material as it is introduced into the container will normally replace any gas that might leak out so as to maintain the desired pressure within the container.

To prevent over inflation of the container, at conventional pressure release valve 18 is provided in the gas supply line which will open when a desired maximum pressure within the container is reached, thereby regulating the pressure within the container.

Gas from the container released by the pressure relief valve 18 is selectively directed by operation of valves 19 and 20 through a pipe 21 into the hopper 13 to pressurize the hopper and to carry any filling material or dust contained in the gas into the hopper, or through a pipe 22 to a conventional gas scrubber or filter 23 to remove any filling material or dust therefrom and recirculated to the pump 10 through a pipe 24. Inert gas or air is otherwise supplied to the pump 10 from a suitable supply source (not shown) through a pipe 10a.

As shown in Fig. 3,. instead of supporting the container by an overhead hoist, the container may be supported on a tiltable cradle 25. The cradle is particularly useful for use with containers having the filling opening in a corner, as illustrated in Fig. 3. The container is placed in the cradle and the cradle tilted about 45 -to bring the filling opening to the highest point of a container thereby insuring filling of the container to its maximum capacity. The cradle 25 includes a base 26 and a curved side 27 corresponding in shape to the cylindrical shape of the container C. The cradle 25 is pivotally supported at each side on an A-frame (only one of which can be seen in Fig. 3). The cradle 25 is tilted by means of fluid cylinder 28 which is pivotally secured at one end to the A-frame and whose piston rod 29a is pivot-ally connected to an arm 30. The arm 30 is secured to the cradle 25. It will be appreciated that the cradle 25 can be used to support the container C during filling with the apparatus shown in Fig. l as well as that shown in Fig. 3. It will also be appreciated that a cradle of the type shown or similar thereto could be fixed to the bed of a truck or railroad platform car so that the container may be tilted and filled without removing the container from the truck or platform car.

The apparatus shown in Fig. 3 differs from that shown in Fig. l in a number of features, any one or all of which could be readily incorporated in the apparatus shown in Fig. 1.

In the apparatus of Fig. 3, the hopper 13 is connected directly to the rotative gas lock valve 15 and the filling material fed by gravity. The gas supply pipe 11 is connected into the conduit 15c forming an integral part of the housing of the air lock valve 15, below the valve 15 so that the inflating gas may be introduced into the container htrough the same filling opening through which the filling material is introduced. By this modification the necessity of a separate inflating opening of the container is eliminated. A baffle or nozzle 31 directs the gas introduced into the conduit 15c towards the container.

- A telescoping filling tube, generally designated by the reference numeral 32 which may be adjusted in length is connected to the conduit by means of a short section of flexible conduit 33. As best shown in Fig. 4 the filling tube 32 consists of two parts, a relatively stationary upper part 32a and a lower movable part 32b which is telescoped over the end of the upper portion 32a. As best shown in Fig. 4 a compressible, annular seal 33 secured to the end of the upper portion 32a presses against theouter surface of the lower portion 32b to prevent leakage of gas between the two parts.

Handles 34 secured to the lower portion 32b of the filling tube 32 serve to facilitate the raising and lowering of the lower portion 32b. Cables 35 secured to the movable lower part 32b of the filling tube 32 and extending around pulleys 36 have weights 37 secured to the ends thereof to counterbalance the weight of the lower telescoping part 32b of the filling tube 32 to facilitate adjustment and movement thereof. In using the modification of Fig. 3, a gas tight connection between the sleeve or sock S of the container C is made prior to inflation of the container. The container is then inflated to its full size and filled while the inflation thereof is maintained.

In Fig. 4A there is shown another form of connection which may be used for forming a gas tight connection between the filling tube 32 and the container C. This connection includes a rigid inner sleeve 38 which is connected to the end of the part 32b of the filling tube 32 by a short section of flexible conduit 39. A flexible, resilient sleeve or annular diaphragm 40 surrounds the rigid sleeve 38 and is secured to the rigid sleeve 38 adjacent each end by means of suitable straps 41. The outer resilient sleeve or diaphragm is adapted to be expanded outwardly by the introduction of air or gas under pressure between the inner rigid sleeve 38 and the outer diaphragm 40. Air or gas under pressure to expand the diaphragm 40 is supplied through a flexible hose 42 which is secured to a rigid pipe 43 which connects with an opening through the inner rigid sleeve 38.

To make the gas tight connection between the filling tube 32 and the container C, the rigid sleeve 38 with the resilient sleeve or diaphragm 40 in collapsed condition is inserted into the filling opening F. Air or gas under pressure is then admitted between the rigid sleeve 38 and the outer diaphragm 40 to expand the diaphragm tightly against the threaded bore of the fitting F surrounding the filling opening F to thereby effect a gas tight seal.

The inflating gas supply arrangement of Fig. 3 is essentially the same as that shown in Fig. l and the same reference numerals have been used to identify the common elements thereof.

The modification of Fig. 5 differs from those shown in Figs. 1 and 3 in that a gun type screw conveyor, generally designated by the reference numeral 44 serves to introduce the filling material into the container through the filling opening F in the container. The advantage of this gun type screw conveyor, in the arrangement illustrated, is that it can be aimed in various directions to direct the filling material to various parts of the container, thereby further insuring complete filling of the container.

The gun type screw conveyor 44 includes an elongated cylindrical barrel 45 in which a conveyor screw 46 is rotatably mounted. The screw 46 is rotatably supported at the discharge end of the barrel 45 by a spider 47 and is secured at the other end to the shaft of an electric motor 48. The motor is provided with a handle 49 by which the'gun conveyor 44 may be aimed. A heavy duty electric hand drill is very satisfactory for use as the motor, in that handles and a trigger switch are commonly provided on such electric drills. The conveyor 44 has an intake opening 51 adjacent the motor end thereof to which is attached one end of a compressible, flexible conduit 51. The conduit 51 is attached at the other end to the rotary gas lock valve 15. The conveyor 44 is suspended on cables 52 which extend over pulleys 53 and have weights 54 secured to the ends thereof to counterbalance the weight of the conveyor 44.

The gas supply hose 12 is connected to an opening 55 through the end of the barrel 45 adjacent the motor end thereof and the gas passes through the barrel 48 into the container C to expand the container prior to filling thereof. Alternatively, gas can be introduced into the conduit 150 as described in connection with the form of apparatus shown in Fig. 3 or directly into the container C through the inflating opening I as described in conjunction with the form of the apparatus shown in Fig. 1. In such cases,'the opening 55 would be closed with a suitable plug.

A substantially gas tight connection is made with the barrel between the barrel 45 of the conveyor 44 and the container. by means of the sock or sleeve S in the manner previously described in conjunction with the forms of the apparatus shown in Figs. 1 and 2. Such a connection permits the gun to be moved inwardly and outwardly of the container to facilitate the filling thereof. The flexibility of the container wall permits the gun to be aimed in various directions to further facilitate the filling.

During filling of the container, the container is preferably vented through a flexible hose 12a connected to the inflating opening I, to prevent excessive pressure build-up in the container. After filling of the container air under pressure may be admitted to the barrel 45 through hose 12 to clean out the barrel. The gas supply system 6 shown in Fig. 5 is otherwise the same as that shown in Figs. 1 and 3 and the same reference numerals have been used for common elements.

The filling opening F in the container is preferably provided adjacent the upper corner of the container to insure complete filling. The conveyor gun 44 is inserted at an angle into the opening and then moved downwardly to a horizontal position as shown. Buckling of the container C around the opening F permits the gun to be moved to this horizontal position. Most of the filling of the container is performed while the conveyor gun 44 is in this horizontal position. When the container is almost full, the conveyor gun 44 is again tilted upwardly so that the container can be filled to capacity. The gun is then removed. The sock S may be tied off before the gun is completely withdrawn from the sock to prevent loss of pressure within the container when the conveyor gun 44 is completely removed.

A fluid actuated cylinder 56 interposed between the chain hoist H and the container C may be used to periodically raise and drop the container a few inches during the filling of the container to thereby jolt the container and compact the filling material.

Referring to Fig. 6, there is shown a modified form of gun conveyor. In this modified form, a rotary gas lock valve 57 is provided as a part of the gun, being rotatably supported in a housing 58 formed as an integral part of the barrel 59 adjacent the motor end. In such an arrangement the valve 15 as shown in Fig. 5 may be eliminated.

The screw 60 is rotatably mounted in an inner barrel 61 which is spaced from the outer barrel 59 so as to provide a passageway 62 through which the inflating gas may pass. A threaded opening 63 is provided in the barrel 59 adjacent the motor end to which the gas supply hose 12 (Fig. 5) may be attached. In inflating the container prior to filling, the inflating gas passes both through the barrel 60 and through the passageway 62. During filling the inflating gas can vent through passageway 62 if the pressure in the container becomes sulficiently high to open the pressure relief valve 18 (Fig. 5).

A gas tight connection is provided between the barrel,

59 and the container by means of a sleeve 64 which is slidably mounted on the barrel 59 and has a threaded end adapted to be threaded into the fitting F of the filling opening F of the container. Lugs 65 are provided on the end of the barrel to prevent the sleeve 64 from sliding off the end of the barrel.

The sleeve 64 is provided with handles 66 to facilitate the threading of the sleeve 64 into the fitting of the filling opening F. A gasket 67 adapted to be compressed between the face of the fitting of the filling opening F of the container and a flange 68 of the sleeve 64 serves to effect a gas tight seal between the sleeve and the fitting.

The barrel 64 of the gun may be slid inwardly and outwardly by reason of the sliding connection with the sleeve 65 to facilitate filling of the container. The barrel can also be aimed in various directions as the wall of the container is sufliciently flexible to permit such.

Referring to Fig. 7, there is shown a pressure regulator and gas cleaner which may be used in place of the pressure relief valve 18 and gas scrubber 23, previously described. The regulator and cleaner, generally designated by the reference numeral 69, includes a cylindrical pipe 70 closed at one end and adapted to carry a fixed height of liquid, such as water. The liquid is supplied to the pipe 70 through a pipe 71. An overflow pipe 72 insures maintenance of a predetermined height of liquid in the container. A pipe 73 adapted to be connected with the gas supply pipe in place of the relief valve 18 of any one of the forms of the apparatus illustrated extends into the pipe 70 so that the inflating system is maintained under a predetermined head of liquid whereby the pressure within the collapsible container is regulated. When the container reaches the desired pressure, excess inflat 7 I ing gas will pass through the pipe 73 and through the liquid in the pipe 70 so that dust and filling material carried thereby will be trapped by the liquid.'

Referring to Fig. 8 there is'shown an impeller attachment which serves to disperse the filling material towards the sides of the container C as the filling material is introduced into the container to further facilitate the complete filling of the container.

The attachment includes a housing 74, which in the form shown has a threaded lower end 75 by which it may be connected to the threaded fitting F of the filling opening F of a container C. A gasket 76 insures that a gas tight seal is provided between the container and the housing 74. Extending through the housing 74 and rotatably supported thereby is a shaft 77. The shaft 77 extends beyond the threaded end 75 and has secured to the end thereof a multi-bladed impeller 78. When the housing 74 is secured to the fitting F, the impeller 78 therefore extends into the container C as illustrated. The'blades 78' of the impeller 78 are pivotally secured to the end of the shaft 77 so that they hang downwardly as shown in solid lines to permit insertion thereof into the container. When rotated the blades 78' extend out wardly by reason of centrifugal force acting therein as indicated by the dashed lines in Fig. 8. I

The filling material is introduced into the container through a branch pipe 79, communicating with and formed as an integral part of the housing 74. The branch is connected with the supply pipe for the filling material, such as the flexible conduit 16 shown in Fig. 1.

The shaft 77 and the impeller 78 secured thereto are rotated by means of an air motor 80 secured to the top of the housing 74. As the filling material is introduced through the branch pipe 79 into the container C, it is thrown towards the sides of the container by the rotating extended blades 78 thereby insuring complete filling of the container. The attachment may be conveniently supported from an eye 81 secured to the top' of the housing 74.

Referring to Fig. 9 the discharging of the filling mate rial from a collapsible container C is illustrated. The

container is suitably supported or suspended over the intake pipe 82 of a suitable screw conveyor 83. The closure plug (not shown) for the discharge opening D is removed and the sock or sleeve S, which had been previously tied off prior to filling of the container, is pulled out and connected to the pipe 82' by means of tie string T, a rubber band or clamp. The intermediate tie string T is then loosened to permit the flow of the filling material therethrough to the conveyor 83 by which it may be conveyed toany desired location.

From the above description it can be seen that there is provided a method and apparatus which will insure complete filling of collapsible containers. The method and apparatus also provides a completely closed system of filling and emptying containers thereby providing dust free operation and insurance against contamination of the lading or filling material, when such is a problem.

It will be appreciated that after filling, the container is preferably further pressurized with air or an inert gas to render the container more rigid so as to facilitate handling, shipping and stacking thereof.

Having thus described my invention, What I claim and desire to protect by Letters Patent is:

l. The method of filling a gas impervious collapsible container with comminuted solids comprising, inflating the collapsible container with gas to a pressure above atmospheric to fully expand the container, preventing said gas under pressure from escaping, and then filling the container with the filling material against the gas pressure while maintaining suflicient gas pressure within the container to hold the container fully expanded during filling.

2. Apparatus for filling .a gas impervious collapsible container with comminuted solids comprising, means for inflating the container with gas to a pressure aboveatmospheric to fully expand the container, means for introducin g the filling material intothe container and .valve means for preventing the escape of the gas and maintaining suflicient gas pressure within the container to hold the container fully expanded during filling.

3. The method of filling a gas impervious collapsible container with comminuted solids comprising, inflating the collapsed container with gas to a pressure above atmospheric to fully expand the container, preventing the escape of the gas, then filling the container with the filling material while maintaining suflicient gas pressure within the container to hold the container fully expanded during filling, and then after filling the container introducing additional gas under pressure into the container to render the container substantially rigid.

4. The method of filling a gas impervious collapsible container with comminuted solids comprising, inflating the collapsed container with a gas inert to the filling material to a pressure above atmospheric to fully expand the container, preventing the escape of the gas, and then filling the container with the filling material while maintaining sufficient gas pressure within the container to hold the container fully expanded during filling.

5. The method of filling a gas impervious collapsible container with comminuted solids comprising, inflating the container with gas through the filling opening of the container to a pressure above atmospheric to fully expand the container and then filling the container by introducing the filling material through the same filling opening in the container while simultaneously maintaining suflicient gas pressure within the container to hold the container fuily expanded during filling.

6. The method of filling a gas impervious collapsible container with comminuted solids comprising, inflating the container with gas through an opening in the container to a pressure above atmospheric to fully expand the container and then filling the container by introducing the filling material through another opening in the container while maintaining sutficient gas pressure within the container to hold the container fully expanded during filling.

7. The method of filling a collapsible container having a flexible sleeve valve associated with the filling opening thereof comprising, closing the sleeve valve inwardly of the free end thereof, inflating the container with gas to fully expand the container, making a gas tight connection between the free end of the sleeve valve and a filling tube through which the filling material is to be passed, then opening the sleeve valve, introducing the filling material through the filling tube and sleeve valve into the container against the gas pressure in the container, maintaining suflicient pressure within the container to hold it fully expanded during filling, then after filling of the container closing the sleeve valve, and then disconnecting the free end of the sleeve valve from the filling tube.

8. Apparatus for filling collapsible containers with comminuted solids comprising, a supply tube through which the filling material may pass into the container, means for making a gas tight connection between the said tube and the collapsible container, a gas lock valve associated with said tube for allowing the filling material to pass into said container while preventing gas under pressure from escaping from said container. 7

9. Apparatus for filling collapsible containers with comminuted solids comprising, a supply tube through which the filling material may pass into the container, means for making a gas tight connection between said tube and the collapsible container, a valve associated with said tube for allowing the filling material to pass into said container while preventing gas under pressure from escaping from said container,- said tube having an opening therein through which gas under pressure can be introduced through said tube into said container to. infiate and expand said container, means for supplying gas under pressure to said opening and means associated with said gas supply means for cleaning gas vented from said container during filling.

10. Apparatus for filling collapsible containers with comminuted solids comprising, a supply tube through which the filling material is adapted to pass into the container, means for making a gas tight connection between said tube and the collapsible container, a valve associated with said tube for allowing the filling material to pass into said container while preventing gas from escaping from said container, said tube having a telescoping portion so that the efifective length of said tube can be varied, and counterbalancing means secured to said telescoping portion to facilitate the movement thereof.

11. Apparatus for filling collapsible containers with comminuted solids comprising, a supply tube through which the filling material is adapted to pass into the container, a screw rotatably mounted in said tube for moving filling material through said tube into said container, a valve associated with said tube through which the filling material can pass into the tube, said valve preventing gas from the container from passing .out through said who, said tube having the opening therein through which gas under pressure can be introduced through said tube into said container to inflate and expand the container, and means for supplying gas under pressure to said opening.

12. The method of filling a gas impervious collapsible container with 'comminuted solids comprising, inflating the collapsible container with gas to a pressure above atmospheric to fully expand the container, filling the container with the filling material while maintaining sufiicient gas pressure within the container to hold the container fully expanded during filling, and dispersing the filling material towards the sides of the container as the filling material is introduced into the container during filling thereof.

13. Apparatus for filling a gas impervious collapsible container with comminuted solids comprising, means for inflating the container with gas to fully expand the container, means for introducing the filling material into the container and valve means for maintaining sufiicient gas pressure within the container to hold the container fully expanded during filling, and means for dispersing the filling material towards the sides of the container as the filling material is introduced into the container during filling.

14. Apparatus for filling collapsible containers with comminuted solids comprising, a supply tube through which the filling material is adapted to pass into the container, a screw rotatably mounted in said tube for moving the filling material through said tube into said container, a valve associated with said tube through which the filling material can pass into the tube, said valve preventing gas from the container from passing out through said tube, a second tube concentric with said first mentioned tube but spaced therefrom to provide a passage way through which gas may pass to and from the container.

15. The method of filling and emptying a collapsible container having a flexible sleeve valve associated with both the filling opening and discharge opening thereof comprising, closing the sleeve valve of both the filling opening and the discharge opening inwardly of the free ends thereof, inflating the container of gas to fully expand the container, making a gas tight connection between the free end of the sleeve valve of the filling opening and a filling tube through which the filling material is to be passed, then opening the sleeve valve of the filling opening, introducing the filling material through the filling tube and sleeve valve into the container against the gas pressure in the container, maintaining sufficient pressure within the container to hold it fully expanded during filling, then after filling the container closing the sleeve valve, and then dis-connecting the free end of the sleeve valve from the filling tube, then making a gas tight connection between the sleeve valve of the discharge opening and a discharge tube, and then after making the connection opening the sleeve valve of the discharge opening to permit the filling material to flow out of the container through the discharge tube.

References Cited inrthe file of this patent UNITED STATES PATENTS 862,231 Bates Aug. 6, 1907 870,215 =-Bates Nov. 5, *1907 1,037,824 Fasting Sept. 3, 1912 1,437,876 Tyler Dec. 5, 1922 1,782,733 Lilly Nov. 25, 1930 2,258,548 Doutrich Oct. 7, 1941 2,596,807 Dippel May 13, 1952 2,720,375 Carter Oct. 11, 1955 FOREIGN PATENTS 521,333 Germany Mar. 21, 1931 

